1. Field of the Invention
The present invention relates to an illuminating device, and more particularly to an intelligent illuminating device in which the light intensity is adjustable according to the brightness level within a designated region so as to provide different illuminating conditions according to user's requirements.
2. Description of Related Art
A conventional power saving lamp comprises a lamp having a CPU (central processing unit), a photoresistor and an infrared sensing unit. The photoresistor couples with the CPU and detects the luminous flux of the environment. The infrared sensing unit couples with the CPU and detects the motions of human beings. Under this arrangement, the photoresistor and the infrared sensing unit can work individually or combinatively; when the infrared sensing unit detects the motions of human beings, a signal is generated and transmitted to the CPU, so that the brightness level of the lamp is adjusted according to the motions of human beings; similarly, when the photoresistor detects the luminous flux of the environment, another signal is generated and transmitted to the CPU, so that the brightness level of the lamp is adjusted for compensating the difference between the luminous flux of the environment and a designated luminous flux.
However, the conventional power saving lamp has several disadvantages.
Firstly, the photoresistor can only universally detect the luminous flux of the environment and cannot detect the luminous flux in a certain orientation corresponding to the photoresistor, so that the applicability of the conventional power saving lamp is serious reduced. Secondly, as mentioned above, because the detection direction of the photoresistor is universal, namely, lacking of directionality, the conventional power saving lamp provides an uneven illuminating condition for a given region.
Thirdly, when a plurality of conventional power saving lamps is applied at the same region, the brightness level of each said lamp cannot be adjusted according to the brightness level of other lamps, so that the brightness level of the region would be excess or insufficient.
Fourthly, in the house, three activity areas are generally defined according to the frequency of activities: a major activity area, a minor activity area and a least activity area. Generally, the requirements for the brightness level of the three areas are different, and the major activity area needs the highest brightness level and the least activity area needs the lowest brightness level. Transitional areas are defined between each two activity areas However, the conventional power saving lamp fails to offer an appropriate illumination level for each area because the photoresistor lacks of directionality; in addition, the brightness level of the transitional areas cannot be adjusted, too; therefore, a brightness difference is undoubtedly existed between the transitional areas and said three activity areas.
Further, to meet the environmental friendly issue, the conventional power saving lamp can be assembled with a solar cell which stores and coverts the sun light into electricity; however, the efficiency of the sun light storage of the solar cell depends on the weather; as mentioned above, because of the lack of directionality of the photoresistor, the brightness level of the conventional power saving lamp cannot be adjusted according to the surrounding environment, so that the conventional power saving lamp wastes a lot of electricity.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional.